Spear gun fishing by underwater divers typically involves the use of a gun that propels a spear towards a fish. When the spear pierces the fish, the fish usually flips and turns through violent contortions to free itself of the spear. Unless the spear tip is fashioned with devices to prevent it from being retracted from the fish, the spear may be shaken loose by the contortions of the fish and the catch is lost.
Currently, spear tips on the market break down into mostly two categories: barb (also known as flopper or wing) and “slip tip.” The barb or flopper is a piece of metal that sits parallel to the spear a few inches back from the point that can pivot on one end to be perpendicular to the spear, holding a fish from sliding off. U.S. Pat. No. 8,677,675 to Koch disclose the barbed version. The slip tip works differently in that once the fish is speared the point itself detaches, turns a certain amount and holds the fish on a tether or line between the point and the spear. U.S. Pat. No. 4,896,450 to Rogers and U.S. Pat. No. 4,624,068 to Howard, II disclose a spear tip of the “slip tip” variety.
The barb is simple and inexpensive to make and replace but does not hold the fish as well as the slip tip does, and it has a tendency to tear out of objects because of its rigidity, losing the object. Further, particularly strong fish can bend and ruin the shaft while pivoting against the barb. The slip tip is effective for catching fish due to its flexible line but is impractical if there is something hard behind the speared object like a rock or reef because it may break upon impact due to its precision machined male and female parts, making it expensive to manufacture. This makes the slip tip impractical in situations where there is a risk of hitting a hard surface by missing the target or shooting through the target and hitting something behind it, for example a fish hiding under a rock. Plus, the slip-tip versions are somewhat less accurate due to having a less than completely secure point leading the shaft trajectory through the water rather than the rigid shaft itself. This limits the type of fish you can spear with either type of tip, requiring a change of tip setup to accommodate objects that the tip cannot successfully snare, and neither tip giving all of the attributes of accuracy, inexpensive replacement cost, durability, effective retaining of the fish, and effective use in a variety of environments on any species of fish.